I followed the mythtv wiki instructions for building MythTV v 0.29. I installed the dependencies from the "Installing Build Dependencies without Ansible" wiki page and included the erroneously excluded libcec-dev (libcec4-dev not available in stretch).

When I run the build-debs script with fixes/29 argument it errors out giving me two errors:

Having exactly the same problem here too. Will try again tomorrow, but hoping for a easy fix.
I ended up building a fresh Debian 9.6 system after I encountered far too much difficulty trying to get the mythtv package to work in a Mint (current/stable) install. Was ready for managing dependencies, but this error threw me for a loop.

Having done a little research and read the readme where it gives examples of fixes, for ubuntu "Version" is something like "0ubuntu" or something like that. Is their a particular version string for debian?

Why don't you open a separate thread about the dependency issue in v 0.28? I would like to get the documentation fixed for building in debian. I know from other posts in this forum (see here: viewtopic.php?t=2646 ) that libcec4-dev is not a dependency for stretch. Apparently the packages in stretch are somewhat different and libcec-dev in stretch is version 4 and there is no libcec4-dev in stretch.

kommisar6: I've abandoned 0.28 in favour of more progress with fixes/29
Like you, I was following https://www.mythtv.org/wiki/Installing_MythTV_on_Debian where it links to "install_build_dependencies_without_ansible". On another thread (lost the link) about building 29 on Ubuntu 18.04 I saw a casual remark about 'assuming' ansible was used to build the dependencies. So tonight I followed the ansible instructions for build dependencies and have managed to get past our problem and compile some (lots) of code.
Unfortunatley I've now met the next hurdle where it exits the compile process thus:

Not at the machine right now, but I did not enable backports specifically. It is a stock 9.6 Cinnamon install with all upgrades applied. The only thing I did was to remove Cinnamon and install XFCE because I'm running an older nVidia card that Cinnamon doesn't like to play nice with.

I know the debian packaging have recently been updated so Launchpad will build and publish them so something may have got broken in the process.

This commit looks like it could be the problem one
github . com/MythTV/packaging/commit/ef03940adc9f62482eece030ef86542f993227aa

I wonder if debian doesn't like the '+' character in the version? You could try changing it to '~' but it needs a debian expert to confirm this is a good fix.

This is the commit that breaks the build script, but not because of the '+', but rather because of the lack of a '-' suffix. I made the following comment on the git commit:

This version number appears to break the build-debs . sh build script in the packaging repo. It parses the changelog and builds a version number from it, but it expects a certain format to the version number. It's looking for a suffix after a hyphen. Without that the script breaks.